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Abstract:

An apparatus for monitoring orthodontic treatment compliance includes an
appliance adapted to be worn over one or more teeth; and a compliance
indicator mounted on the appliance to indicate compliance.

Claims:

1. An apparatus for monitoring orthodontic treatment compliance, the
apparatus comprising:an appliance adapted to be worn over one or more
teeth; anda compliance indicator mounted on the appliance to indicate
compliance by demonstrating a change in at least one characteristic of
the indicator, wherein the changed characteristic comprises at least one
of color, shape, and size.

2. The apparatus of claim 1, wherein the appliance is used in conjunction
with treatment for a predetermined period of time.

3. The apparatus of claim 1, wherein the compliance is visually,
chemically, or physically indicated.

4. The apparatus of claim 1 wherein the change is affected by at least one
of: moisture, temperature, one or more chemicals, and one or more
biological substances.

5. The apparatus of claim 1, wherein the change is detectable by human or
machine vision.

6. The apparatus of claim 1, wherein the change is affected by a
degradation of a biodegradable or a dissolvable polymer.

7. The apparatus of claim 1, wherein the compliance is indicated by a loss
in size of the indicator.

8. The apparatus of claim 1, wherein the compliance is indicated by
exposure of a colored material previously hidden under a polymeric layer
of the appliance.

9. The apparatus of claim 8, wherein the color exposure occurs after
degradation or dissolution of the polymeric layer.

10. The apparatus of claim 1, wherein the compliance is indicated by a
color change.

11. The apparatus of claim 10, wherein the color change occurs due to a
reaction between one or more materials in the indicator and one or more
oral fluids.

13. The apparatus of claim 12, wherein compliance is indicated by a
concentration change of ingredients in oral fluids.

14. The apparatus of claim 12, wherein compliance is indicated by an
absence of a change while the appliance is worn.

15. The apparatus of claim 1, wherein the compliance is indicated by a
chemical reaction through a semi-permeable membrane.

16. The apparatus of claim 1, wherein the compliance is indicated by a
mechanical deformation during orthodontic movement.

17. The apparatus of claim 1, wherein the change is affected by a change
in electrical resistance of at least part of the indicator.

18. The apparatus of claim 17, wherein the indicator includes one or more
conducting fillers.

19. The apparatus of claim 1, wherein the change is affected by a mass
transfer or a chemical reaction.

20. The apparatus of claim 1, wherein compliance is determined by use of
the appliance over the teeth for a prolonged period of time.

21. The apparatus of claim 1, wherein the appliance is configured to
adjust a configuration of the teeth.

22. An apparatus for monitoring orthodontic treatment compliance, the
apparatus comprising:an appliance adapted to be worn over one or more
teeth; anda compliance indicator mounted on the appliance to indicate
compliance by demonstrating a change in at least one characteristic of
the indicator, wherein the changed characteristic comprises at least one
of shape and size.

Description:

PRIORITY INFORMATION

[0001]This application is a Continuation-in-Part of U.S. patent
application Ser. No. 10/949,717 filed Sep. 24, 2004, and a Continuation
in Part of U.S. patent application Ser. No. 11/745,211 filed May 7, 2007
which is a Divisional of U.S. patent application Ser. No. 09/666,783
filed Sep. 21, 2000 now U.S. Pat. No. 6,607,382, the specifications of
which are incorporated herein by reference.

[0003]As noted in commonly owned U.S. Pat. No. 6,607,382 entitled "Methods
and systems for concurrent tooth repositioning and substance delivery,"
the content of which is incorporated herewith, the repositioning of teeth
may be accomplished with the use of a series of removable elastic
positioning appliances such as the Invisalign® system available from
Align Technology, Inc., the assignee of the present invention. Such
appliances have a thin shell of elastic material that generally conforms
to a patient's teeth but is slightly out of alignment with an initial or
immediately prior tooth configuration. Placement of the elastic
positioner over the teeth applies controlled forces in specific locations
to gradually move the teeth into the new configuration. Repetition of
this process with successive appliances comprising new configurations
eventually moves the teeth through a series of intermediate
configurations or alignment patterns to a final desired configuration. A
full description of an exemplary elastic polymeric positioning appliance
is described in U.S. Pat. No. 5,975,893, and in published PCT application
WO 98/58596, the content of these documents are incorporated by reference
for all purposes.

[0004]The appliance is effective in repositioning teeth when it is placed
over the patients teeth. Although easy and convenient to wear, the
patient may not wear the appliance as prescribed by the doctor or
orthodontist. Extended removal of the appliance, for any reason beyond
what is recommended, interrupts the treatment plan and lengthens the
overall period of treatment. Since the appliance is removable by the
patient, the doctor has to rely on the patient to comply with the
prescription.

BRIEF DESCRIPTION OF THE DRAWINGS

[0005]FIG. 1 shows an exemplary compliance indicator.

[0006]FIGS. 2A-2C show a first embodiment of the compliance indicator of
FIG. 1.

[0007]FIGS. 3A-3B show a second embodiment of the compliance indicator of
FIG. 1.

[0008]FIGS. 4A-4B show a third embodiment of the compliance indicator.

[0020]FIG. 16 illustrates a reservoir type releasing means that is
accessible to the user so that the reservoir may be replenished with an
agent.

[0021]FIG. 17 is a cross-sectional view of an appliance having a binding
material and releasably bound agent applied to its surface.

[0022]FIG. 18 is a cross-sectional view of an appliance comprised of a
controlled-release material containing an agent.

[0023]FIG. 19 illustrates a gradual color change of an appliance from
transparent to colored as the appliance changes in temperature.

[0024]FIG. 20 depicts the use of a color or dye localized in a specific
area; examples of a stripe formed in the appliance and a portion of
colored material affixed to a surface are shown.

SUMMARY

[0025]An apparatus for monitoring orthodontic treatment compliance
includes an appliance adapted to be worn over one or more teeth; and a
compliance indicator mounted on the appliance or teeth to indicate
compliance.

[0026]Advantages of the system include one or more of the following. The
apparatus provides better data for communicating device compliance with
patients, including: increased patient knowledge and recall of appliance
usage; increased compliance in wearing the dental appliance, and
increased patient satisfaction as a result. The apparatus provides a
channel of self-monitoring for the patient. The apparatus also reduces
patient's anxiety levels without requiring verbal or written instructions
since device usage is self-evident. The doctor or orthodontist also has
better information on patient progress during the treatment.

[0027]The present invention provides devices, systems and methods for
orthodontic treatment using repositioning appliances, typically elastic
polymeric shells, while concurrently delivering substances to the teeth
or gums, for example, to provide dental and periodontal and/or cosmetic
therapies. Such therapies are traditionally provided with the use of a
variety of accessories and devices which are applied using separate
appliances, materials, etc. The present invention eliminates the need for
such additional devices by incorporating these therapies into the
repositioning appliance. Moreover, the ability to deliver therapeutic and
other agents is concurrent with the course of a repositioning procedure.

[0028]By "concurrent" or "concurrently," it is meant that the substance or
agent delivery to the teeth occurs during at least a portion of the
duration of the repositioning of the teeth. Thus, the substance may be
delivered continuously during the entire duration of the repositioning
process, i.e. the substance may be present in or on each repositioning
appliance in an amount or amounts sufficient to assure that it is
released to the oral environment at all times the appliance is placed
over the teeth. Alternatively, the substance may be present in or on the
repositioning appliances at only selected times or over selected time
intervals so that the substances are delivered at spaced-apart times
during the repositioning process. For example, each successive
repositioning appliance may be preloaded with a bolus of the substance so
that the bolus is delivered to the patient at the outset of use of each
new appliance. After the initial bolus is depleted, the substance will
not be delivered again until the next successive appliance is used. As an
alternative example, the patient could apply an amount of a substance at
a time each day, where the substance is then released over a relatively
short time interval and no more substance delivered until the next day. A
multitude of other particular patterns are also possible.

[0029]While the appliances will be particularly intended for repositioning
teeth, most often when used in systems of multiple aligners, they may in
some instances be useful as drug or substance delivery devices without
the concurrent repositioning of teeth. In particular, many of the
specific device constructions described below are themselves novel and
useful for substance delivery, and the present invention encompasses such
devices.

[0030]In a first aspect of the present invention, an oral delivery
appliance comprises an elastic repositioning appliance providing one or
more substances or agents for oral delivery. As previously described,
elastic repositioning appliances comprise a thin shell of elastic
polymeric material having cavities shaped to receive and resiliently
reposition teeth from one arrangement to a successive arrangement. This
is possible because the cavities are shaped to fit a mold of digitally
arranged teeth in the successive arrangement. A full description of an
exemplary elastic repositioning appliance shaped in this manner is
described in U.S. Pat. No. 5,975,893, and in published PCT application WO
98/58596. Placement of the elastic positioner over the teeth applies
controlled forces in specific locations to gradually move the teeth into
the new configuration. In order to apply sufficient force, the appliance
generally covers the tooth surfaces and portions of the gingival margin.
Thus, both individual repositioning appliances and systems of such
elastic repositioning devices may be used to deliver agents to the
underlying tooth surfaces and gingiva comprising the oral environment
while repositioning teeth.

[0031]In a first embodiment, the oral delivery appliance delivers fluoride
to the oral environment to prevent or treat tooth decay. Traditionally,
fluoride has been delivered to the oral environment through the use of
toothpastes, gels, rinses and varnishes, to name a few. The present
invention provides fluoride delivery which may be used in conjunction
with traditional applications or may replace certain applications. Such
fluoride may be provided in a number of forms, such as neutral sodium
fluoride, stannous fluoride, hydrogen fluoride, or acidulated phosphate
fluoride (APF) gel, for example. Fluoride may be releasably attached to
the elastic repositioning appliance in a number of forms, as will be
described in more detail in later sections, to provide delivery to the
oral environment.

[0032]In a second embodiment, the oral delivery appliance delivers an
antibiotic or drug to the oral environment. In the case of antibiotics,
delivery of such an agent may inhibit or kill various microorganisms.
Antibiotics often used to treat gingivitis and periodontitis include
chlorhexidine and tetracycline. Such antibiotics may be releasably
attached to the elastic repositioning appliance in a number of forms, as
will be described in more detail in later sections, to provide delivery
to the oral environment.

[0033]In a third embodiment, the oral delivery appliance delivers a
bleaching material to the oral environment. Bleaching of the teeth is a
common cosmetic procedure requested of dental practitioners by their
patients. The active ingredient in standard bleaching gels is carbamide
peroxide and is typically present in an 18-37% suspension. Bleaching
materials, such as carbamide peroxide, may be releasably attached to the
elastic repositioning appliance in a number of forms, as will be
described in more detail in later sections, to provide delivery to the
oral environment.

[0034]In a fourth embodiment, the oral delivery appliance delivers a
breath freshener to the oral environment. Breath fresheners are commonly
available in a number of flavors and scents, including mint and fruit
flavors, derived from essential oils and/or natural or artificial
flavorings, to name a few. Such breath fresheners may be releasably
attached to the elastic repositioning appliance in a number of forms, as
will be described in more detail in later sections, to provide delivery
to the oral environment.

[0035]In a second aspect of the present invention, at least some of the
elastic repositioning appliances in a system for repositioning teeth are
coupled to means for releasing the agent to the oral environment when the
appliance is placed over the teeth. Such means may comprise a layer which
includes the agent. The layer may be formed over at least a portion of
the surfaces of the repositioning appliance. These surfaces include both
the cavity surfaces, the surfaces within the cavities which contact the
teeth when in place, and the external surfaces, the surfaces of the
appliance which contact the cheeks and lips when in place. The layer may
be comprised of various materials and may take a variety of forms. For
example, the layer may consist essentially of the agent. In other words,
the agent may be attached directly to a surface of the polymer shell of
an elastic repositioning appliance. This may be achieved by applying the
agent (optionally in an inert carrier or diluent) itself to the surface
utilizing a number of methods, such as spraying, painting and/or dipping.
When the repositioning appliance is placed over the patient's teeth, the
agent may then be released to the oral environment.

[0036]Alternatively, the layer may comprise the agent present in or on a
carrier or binder which promotes adhesion or attachment to the appliance
and/or which creates a matrix from which the agent can be released by
diffusion or dissolution. In one embodiment, the agent is dissolved in
the carrier or binder. In this case, the agent may be provided in powder
or similar form and dissolved in a liquid solvent. The result may be a
solution which may be applied to a surface of the shell, typically by
spraying, painting and/or dipping, to form a coating or film. When the
repositioning appliance is placed over the patient's teeth, the agent may
then be released from the coating to the oral environment. Release may be
due to activation or deactivation of the carrier or any other releasing
mechanism, such as by enzymes or proteins in saliva. Or release may be
due to degradation of the carrier by contact with, for example, saliva.
In some cases, the binder or carrier may evaporate upon application to
the layer to the surface leaving the agent behind. In these cases, the
agent may be released in a similar fashion as when the agent is directly
attached to the surface, as described above. It may be appreciated that
any agent, particularly fluoride materials, antibiotics, bleaching
materials and breath fresheners, may be delivered to the oral environment
in this manner.

[0037]In another embodiment, the agent is encapsulated or suspended in the
layer. A common material for suspension of an agent is a semisolid
material, such as a gel, jelly or putty. Such a material may be applied
to a surface of the shell by spraying, painting and/or dipping to form a
coating or film. Here, as in all cases, suspension is not limited to a
scientific definition and may refer to any situation in which a carrier
holds, contains, supports or otherwise includes an agent. Alternatively
or in addition, the semisolid material may be deposited in the cavities
of the polymer shell which are shaped to receive the teeth. The cavities
may be filled to any desired level. When the repositioning appliance is
positioned over the teeth, the teeth will directly contact the semisolid
material in the cavities and displace any extra material as the teeth are
inserted into the cavities. Therefore, it is desired to fill the cavities
to a level which will avoid excess overflow of the material from the
appliance. Delivery of an agent by use of a semisolid suspension material
is common in bleaching treatments and fluoride treatments, for example.
However, such treatments apply the material with the use of a tray or
generic appliance which does not apply repositioning forces to the teeth.
By modifying a repositioning appliance, as described above, orthodontic
treatment may continue throughout the delivery of such agents. It may be
appreciated that any agent, particularly fluoride materials, antibiotics,
bleaching materials and breath fresheners, may be delivered to the oral
environment in this manner.

[0038]Another common material for encapsulation or suspension of an agent
is a controlled-release material. Thus, the layer may be comprised of a
rate-controlling material wherein the rate controlling material controls
the rate at which the agent is released from the layer.
Controlled-release or rate-controlled materials deliver a predetermined
amount of an agent at a predetermined rate. Often such delivery maintains
a steady-state concentration of an agent in an environment within a
desired therapeutic range for a prolonged period of time. Thus, a
prescribed dosage may be delivered. In addition, the ability to sustain
delivery eliminates the need for repeated applications of the agent for
dosed delivery to the oral environment.

[0039]Although such controlled release materials may be provided as a
semisolid material, such as a gel, jelly or putty, as described above,
these materials may also be provided as a solid material which is
attached to the polymeric shell of the repositioning appliance. One type
of controlled-release material comprises a polymer matrix membrane within
which finely dispersed particles of an agent are suspended. The agent may
diffuse through the matrix membrane according to a concentration
gradient. Alternatively or in addition, the agent may be released by
degradation of the polymer matrix membrane material. In either case, the
controlled-release material may be provided as a sheet which may be
laminated to a surface of the shell. The controlled-release sheet may be
layered with the elastomeric polymer and vacuum formed over a mold to
form the repositioning appliance. The controlled-release material may be
arranged so that it is present on the inside or outside surfaces of the
appliance depending on the material and desired application. Or, the
controlled-release sheet may be laminated or bonded to a surface of the
polymeric shell after forming to supply agent delivery in desired areas.
Alternatively, the controlled-release material may be provided as a
tablet or similar mass which may be inserted into the polymeric shell of
the repositioning appliance. The agent may then elute from the tablet
into the oral environment over time.

[0040]In another embodiment, the agent may be held within pores of a
material and may elute out at a controlled rate from the pores. The agent
itself may be absorbed into the pores of the material, or the agent may
be suspended in a carrier which is absorbed into the pores of the
material. In the latter case, the agent may be released from the carrier
by diffusion and/or by controlled degradation of the carrier material.
This may incorporate a rate-controlling mechanism in addition to the
controlled-release of the agent from the pores. As mentioned, in some
cases, enzymes in the patient's saliva will activate the release or
degrade the carrier material to release the agent. It may be appreciated
that the agent may be released by a combination of any of the release
methods.

[0041]In a further embodiment, the polymeric shell of the repositioning
appliance itself comprises a controlled-release material containing the
agent. In this case, at least a portion of at least some of the polymeric
shells in a system for repositioning teeth are formed from a controlled
release material wherein the rate controlling material controls the rate
at which the agent is released from the shell. As previously described,
the controlled-release material may be a provided in the form of a sheet.
Thus, the sheet of controlled-release material may be vacuum formed over
a mold of the patient's teeth to form a repositioning appliance itself.
In this manner, no additional elastomeric materials may be needed to form
the appliance. The controlled-release material may be a polymer matrix
membrane, a porous material or any suitable material. Controlled-release
may be designed so that the elution rate of the agent corresponds to the
repositioning rate of the teeth. The agent may elute throughout the
repositioning process, concluding as the teeth reach the desired
arrangement prescribed by the appliance.

[0042]In a still further embodiment, the releasing means coupled to at
least some of the repositioning appliances comprises a reservoir formed
in the shell of the appliance in addition to the cavity which receives
the teeth. Typically, a rate controlling membrane is disposed over the
reservoir wherein the rate controlling membrane controls the rate at
which the substance is released from the reservoir. The reservoir may be
pre-filled or pre-loaded with an agent or substance for delivery. In this
case, the appliance may be ready for insertion or use upon removal from
any packaging without the need of loading the appliance with the agent
for delivery. If the releasing means is designed for a single delivery
period, the appliance may be worn throughout the prescribed repositioning
period and then disposed of. If the releasing means is designed for
multiple delivery periods, the reservoir may be replenished with the
agent to be released any number of times throughout the prescribed
repositioning period. It may be appreciated that any agent, particularly
fluoride materials, antibiotics, bleaching materials and breath
fresheners, may be delivered to the oral environment in this manner.

[0043]In some instances, it may be desirable to change a visual
characteristic of the polymeric shell of an oral appliance. Such
appliances comprise a polymeric shell having a cavity shaped to be
removably placeable over the teeth and a material on or within the shell
that changes a visual characteristic of the shell. Such a change is
typically in response to a change in the environment. In some cases, the
visual characteristic is a color, such as green, red or blue. Thus, the
appliance may appear colored or a particular color under certain
environmental conditions, either in the oral environment or when removed.
The described material may be a dye which changes color in response to a
change in temperature. For example, the dye may change color when the
appliance is removed from the mouth and changes temperature from body
temperature (37° C.) to room temperature (25° C.).
Similarly, the dye may change color when the appliance is rinsed with
cool water.

[0044]Other objects and advantages of the present invention will become
apparent from the detailed description to follow, together with the
accompanying drawings.

DESCRIPTION

[0045]FIG. 1 shows an exemplary removable appliance 15 adapted to fit over
teeth on a jaw 16. A usage indicator 100 can be mounted on one tooth or
on the appliance 15 to indicate patient compliance.

[0046]In one implementation, the indicator 100 can be a coat on a tooth or
an appliance with a chemical agent. Alternatively, the indicator 100 can
be an electrical agent, optical agent or mechanical agent that indicates
appliance wearage. In one embodiment, the indicator agent is inactive
until contact with liquid or moisture. Alternatively, release of the
agent can be stimulated by liquid or moisture. Thus, in one case, upon
wearing, oral fluids activates the agent and allows the agent to seep out
and indicate compliance. Alternatively, oral fluids such as saliva, among
others, can seep in to activate the agent to indicate compliance.

[0047]In another embodiment, the appliance can release a coloring agent to
the oral environment when the appliance is worn over the teeth. Such
means may comprise a layer which includes the agent. The layer may be
formed over at least a portion of the surfaces of the repositioning
appliance. These surfaces include both the cavity surfaces, the surfaces
within the cavities which contact the teeth when in place, and the
external surfaces, the surfaces of the appliance which contact the cheeks
and lips when in place. The layer may be comprised of various materials
and may take a variety of forms. For example, the layer may consist
essentially of the agent. In other words, the agent may be attached
directly to a surface of the polymer shell of an elastic repositioning
appliance. This may be achieved by applying the agent (optionally in an
inert carrier or diluent) itself to the surface utilizing a number of
methods, such as spraying, painting and/or dipping. When the
repositioning appliance is placed over the patient's teeth, the agent may
then be released to the oral environment.

[0048]Alternatively, the layer may comprise the agent present in or on a
carrier or binder which promotes adhesion or attachment to the appliance
and/or which creates a matrix from which the agent can be released by
diffusion or dissolution. In one embodiment, the agent is dissolved in
the carrier or binder. In this case, the agent may be provided in powder
or similar form and dissolved in a liquid solvent. The result may be a
solution which may be applied to a surface of the shell, typically by
spraying, painting and/or dipping, to form a coating or film. When the
repositioning appliance is placed over the patient's teeth, the
compliance indicating agent may then be released from the coating to the
oral environment. Release may be due to activation or deactivation of the
carrier or any other releasing mechanism, such as by enzymes or proteins
in oral fluids. Or release may be due to degradation of the carrier by
contact with, for example, oral fluids. In some cases, the binder or
carrier may evaporate upon application to the layer to the surface
leaving the agent behind. In these cases, the agent may be released in a
similar fashion as when the agent is directly attached to the surface, as
described above. It may be appreciated that any agent, particularly
fluoride materials, antibiotics, bleaching materials and breath
fresheners, may be delivered to the oral environment in this manner.

[0049]In another embodiment, the agent is encapsulated or suspended in the
layer. A common material for suspension of an agent is a semisolid
material, such as a gel, jelly or putty. Such a material may be applied
to a surface of the shell by spraying, painting and/or dipping to form a
coating or film. Here, as in all cases, suspension is not limited to a
scientific definition and may refer to any situation in which a carrier
holds, contains, supports or otherwise includes an agent. Alternatively
or in addition, the semisolid material may be deposited in the cavities
of the polymer shell which are shaped to receive the teeth. The cavities
may be filled to any desired level. When the repositioning appliance is
positioned over the teeth, the teeth will directly contact the semisolid
material in the cavities and displace any extra material as the teeth are
inserted into the cavities. Therefore, it is desired to fill the cavities
to a level which will avoid excess overflow of the material from the
appliance. Delivery of an agent by use of a semisolid suspension material
is common in bleaching treatments and fluoride treatments, for example.
However, such treatments apply the material with the use of a tray or
generic appliance which does not apply repositioning forces to the teeth.
By modifying a repositioning appliance, as described above, orthodontic
treatment may continue throughout the delivery of such agents. It may be
appreciated that any agent, particularly fluoride materials, antibiotics,
bleaching materials and breath fresheners, may be delivered to the oral
environment in this manner.

[0050]Another common material for encapsulation or suspension of an agent
is a controlled-release material. Thus, the layer may be comprised of a
rate-controlling material wherein the rate controlling material controls
the rate at which the agent is released from the layer.
Controlled-release or rate-controlled materials deliver a predetermined
amount of an agent at a predetermined rate. Often such delivery maintains
a steady-state concentration of an agent in an environment within a
desired therapeutic range for a prolonged period of time. Thus, a
prescribed dosage may be delivered. In addition, the ability to sustain
delivery eliminates the need for repeated applications of the agent for
dosed delivery to the oral environment.

[0051]Although such controlled release materials may be provided as a
semisolid material, such as a gel, jelly or putty, as described above,
these materials may also be provided as a solid material which is
attached to the polymeric shell of the repositioning appliance. One type
of controlled-release material comprises a polymer matrix membrane within
which finely dispersed particles of an agent are suspended. The agent may
diffuse through the matrix membrane according to a concentration
gradient. Alternatively or in addition, the agent may be released by
degradation of the polymer matrix membrane material. In either case, the
controlled-release material may be provided as a sheet which may be
laminated to a surface of the shell. The controlled-release sheet may be
layered with the elastomeric polymer and vacuum formed over a mold to
form the repositioning appliance. The controlled-release material may be
arranged so that it is present on the inside or outside surfaces of the
appliance depending on the material and desired application. Or, the
controlled-release sheet may be laminated or bonded to a surface of the
polymeric shell after forming to supply agent delivery in desired areas.
Alternatively, the controlled-release material may be provided as a
tablet or similar mass which may be inserted into the polymeric shell of
the repositioning appliance. The agent may then elute from the tablet
into the oral environment over time.

[0052]In another embodiment, the agent may be held within pores of a
material and may elute out at a controlled rate from the pores. The agent
itself may be absorbed into the pores of the material, or the agent may
be suspended in a carrier which is absorbed into the pores of the
material. In the latter case, the agent may be released from the carrier
by diffusion and/or by controlled degradation of the carrier material.
This may incorporate a rate-controlling mechanism in addition to the
controlled-release of the agent from the pores. As mentioned, in some
cases, enzymes in the patient's oral fluids will activate the release or
degrade the carrier material to release the agent. It may be appreciated
that the agent may be released by a combination of any of the release
methods.

[0053]In a further embodiment, the polymeric shell of the repositioning
appliance itself comprises a controlled-release material containing the
agent. In this case, at least a portion of a polymeric shell is formed
from a controlled release material wherein the rate controlling material
controls the rate at which the agent is released from the shell. As
previously described, the controlled-release material may be a provided
in the form of a sheet. Thus, the sheet of controlled-release material
may be vacuum formed over a mold of the patient's teeth to form a
repositioning appliance itself. In this manner, no additional elastomeric
materials may be needed to form the appliance. The controlled-release
material may be a polymer matrix membrane, a porous material or any
suitable material. Controlled-release may be designed so that the elution
rate of the agent corresponds to the repositioning rate of the teeth. The
agent may elute throughout the repositioning process, concluding as the
teeth reach the desired arrangement prescribed by the appliance.

[0054]In a still further embodiment, the releasing means coupled to at
least some of the repositioning appliances comprises a reservoir formed
in the shell of the appliance in addition to the cavity which receives
the teeth. Typically, a rate controlling membrane is disposed over the
reservoir wherein the rate controlling membrane controls the rate at
which the substance is released from the reservoir. The reservoir may be
pre-filled or pre-loaded with an agent or substance for delivery. In this
case, the appliance may be ready for insertion or use upon removal from
any packaging without the need of loading the appliance with the agent
for delivery. If the releasing means is designed for a single delivery
period, the appliance may be worn throughout the prescribed repositioning
period and then disposed of. If the releasing means is designed for
multiple delivery periods, the reservoir may be replenished with the
agent to be released any number of times throughout the prescribed
repositioning period. It may be appreciated that any agent, particularly
fluoride materials, antibiotics, bleaching materials and breath
fresheners, may be delivered to the oral environment in this manner.

[0055]In some instances, it may be desirable to change a visual
characteristic of the polymeric shell of an oral appliance. Such
appliances comprise a polymeric shell having a cavity shaped to be
removably placeable over the teeth and a material on or within the shell
that changes a visual characteristic of the shell. Such a change is
typically in response to a change in the environment. In some cases, the
visual characteristic is a color, such as green, red or blue. Thus, the
appliance may appear colored or a particular color under certain
environmental conditions, either in the oral environment or when removed.
The described material may be a dye which changes color in response to a
change in temperature. For example, the dye may change color when the
appliance is removed from the mouth and changes temperature from body
temperature (37° C.) to room temperature (25° C.).
Similarly, the dye may change color when the appliance is rinsed with
cool water.

[0056]The appliance can be used to provide an intra-oral drug delivery
system. In addition to the agents described above, other compounds can be
used as well. For example, a drug coated appliance can be used to deliver
desensitizing medication to sensitive teeth. The drug substance can
simply be a small amount of the active ingredient in a desensitizing
toothpaste or gel, such as Sensodyne®. The desensitizing agent is
dispersed throughout the surface of the appliance and is delivered, at a
substantially constant rate, to the patient's sensitive teeth for a
relatively extended period of time.

[0057]Although the appliance may be pre-loaded with the agent and ready
for use upon removal from any packaging, appliances that are not
pre-filled or pre-loaded may require loading prior or immediately prior
to placing the appliance over the teeth. Loading may comprise placing the
agent in a teeth-receiving cavity. As described previously, the cavities
may be filled to any desired level. When the appliance is positioned over
the teeth, the teeth will directly contact the agent in the cavities as
the teeth are inserted into the cavities. Alternatively, loading may
comprise placing the agent into an agent release reservoir in the
appliance immediately prior to placing the appliance over the teeth. The
agent will then elute from the reservoir into the oral environment when
the appliance is in place over the teeth. The elution rate may be
controlled by a controlled release membrane which separates the reservoir
from the surrounding environment. Loading may also comprise adhering a
rate controlling material containing the agent to a surface of the
appliance prior to placing the appliance over the teeth. Such a material
may comprise a polymer matrix membrane which may be removably or
permanently adhered to the polymeric shell of the appliance in desired
areas for delivery of the agent. And finally, loading may comprise
absorbing the agent into a porous material on or within the appliance
immediately prior to placing the appliance over the teeth.

[0058]Means for releasing the agent may include a number of embodiments,
including any such means previously described. Typically, means for
releasing the agent comprises a layer including the agent, as previously
described, and coupling comprises adhering the layer to at least a
portion of a surface of the appliance. When the layer consists
essentially of the agent, adhering may involve coating, spraying, dipping
or painting the agent on the surface of the appliance. Thus, a pre-formed
appliance may simply be coated with the agent prior to insertion in the
patients mouth. When the layer comprises an agent present in or on a
carrier or binder, adhering may involve attaching the carrier or binder a
surface of the appliance. Similarly, when the agent is encapsulated in
the layer, the layer may be attached to the surface of the appliance. The
layer may comprise a sheet of rate controlling material wherein the rate
controlling material controls the rate at which the agent is released
from the layer. In this case, the sheet may be bonded to the surface of
the appliance with an adhesive. Alternatively, the sheet may be attached
to the surface by press fitting. The sheet and the surface may each be
shaped so that they snap or fit together by pressing them together. For
example, the sheet may have a formed protrusion and the surface a formed
inset, wherein the protrusion fits into the inset when pressed upon the
inset and holds the sheet in place. In many instances, the appliance may
be porous or have a reservoir which can be loaded with a desired agent at
any time the treating professional and/or the patient decide that it is
appropriate. For example, an appliance can be immersed in a solution of
the agent, allowing the appliance to absorb or adsorb the agent at a
particular time.

[0059]In addition, the sheet may be preformed to a shape adapted for
fitting against the surface of the appliance or a surface of the teeth or
gingiva. For example, the sheet may be pre-formed to reflect the shape of
the surface of one or more teeth or the gingiva, particularly along the
gingival margin. The preformed sheet may then be held against that
surface when the sheet is coupled to the appliance and the appliance is
placed over the teeth. Coupling may involve any means of attaching the
sheet to the appliance. In particular, the pre-formed sheet may further
comprise an adhesive layer which may provide bonding of the sheet to the
surface of the appliance.

[0060]The material to make to the appliance of FIG. 1 can be supplemented
with additional fillers such as electrically conducting fillers, magnetic
fillers, illuminating fillers, piezoelectric fillers, and/or light
sensitive fillers. The material properties of the appliance made with or
without these additional fillers such as modulus, electrical resistance,
material permeability, and birefringence (degree of orientation of the
material or stress), illuminating patterns or patterns under special
light sources may change after the appliance is worn over time, as these
properties are altered due to changes in structure, organization, and/or
spatial spacing between the fillers. For example, it is well established
that electrical conductivity of filled composites scales with filler
volume concentration according to percolation theory. Therefore,
mechanical deformation or thermal expansion of the non-conductive polymer
matrix will lead to increased average inter-filler spacing, or decreased
filler volume concentration, and consequently decreased electrical
conductivity. Examples of electrically conductive fillers include metals,
graphite, electrically conductive polymers, semiconductors, and
superconductors. These changes in properties can be used as an indicator
for compliance and can be diagnosed by instrumentation. Similarly,
separation of conductive fillers will also lower thermal conductivity,
which can also be measured by instrumentations. If the fillers have
magnetic behavior in the presence of external stimulation, such as
diamagnetics (Cu, Au, Ag, etc.) and paramagnetics (e.g. Al, Cr, Na, Ti,
Zr, etc.); or exhibit intrinsic magnetic properties, such as
ferromagnetics (Fe, Co, Ni, etc.), antiferromagnetics (e.g. MnO), and
ferromagnetics (MFe2O4), then separation of the filler spacing due to
mechanical deformation of the polymer matrix can also lead to decreases
in magnetic properties above the Curie temperature. Mechanical
deformation of composites with illuminating fillers, such as those that
exhibit luminescence, fluorescence, or phosphorescence, will result in
decreased illumination intensity. Bending deformation or displacement of
piezoelectric fibers can result in electrical potentials which can be
either measured, or used to activate other electrically driven indicators
(e.g. low power LED light). Fillers with optical properties which depend
on external electric field, for example those that shift their absorption
coefficients in the UV, IR, or visible spectrum can also serve as
indicator of matrix deformation.

[0061]Referring now to FIG. 2A, an embodiment of an indication attachment
device 200 is shown. The indication attachment device 200 includes a
polymer well 201, and the well 201 includes a semi-permeable membrane
202. The membrane 202 allows a two-way flow between the well 201 and an
interface to the oral environment. Within the well 201, a material 204
such as a dyed material is provided.

[0062]In one embodiment, the dyed material 204 is a releasable material,
such as dyed poly(vinylsiloxane) (PVS) material. The PVS material is used
to hold the dye, and the membrane 202 can be a cellulose acetate
membrane. Those skilled in the arts will understand that other releasable
materials such as polyether, polyurethane, ethyl vinyl acetate can also
be manipulated to result in the teachings of this patent.

[0063]In another embodiment, the material 204 can be an enzyme or a
reactor that reacts with enzymes from the oral fluids. When oral fluids
or enzyme from the oral fluids enters the well, the material 204 reacts
with the enzyme to provide an indication. Alternatively, a pH indicator
can be used as the material 204. In yet another embodiment, the membrane
202 can be silicon instead of PVS.

[0064]In another embodiment, the polymer can be water-soluble polymer that
includes water-soluble polymers, lightly cross-linked hydrogels, and high
molecular weight with hydrogen bonding plastics that demonstrate some
limited water resistance. Natural-based water-soluble polymers include
starch, starch-oxided, cellulose, cellulose-alkoxylated,
cellulose-carboxyalkylated, chitin, chitosan, pectins, hyaluronic acid,
proteins, and lignin. Water-soluble polymers can also be created from
synthetic raw material through polymerization by addition/vinyl,
condensation, and ring-opening. Examples of these types of polymers are
poly(vinyl alcohol), polyesters, and poly(alkylene oxides). The
hydrolytic instability of biodegradable polymers is advantageous because
the presence of the oral fluids will facilitate the degradation of the
polymer.

[0065]Referring now to FIG. 2B, a cross-sectional view of the compliance
indication attachment device (compliance indicator) 200 is shown. As
viewed therein, the membrane 202 is positioned above the polymer well,
chamber or housing 201 with the releasable material and or dye 204
enclosed therein. As shown in FIG. 2c, after a predetermined period of
time, for example two weeks, a portion of the dyed PVS material 204 has
seeped out causing a change in appearance of the indication attachment
device. The dye is released while the PVS stays inside the device. In
this case, a color change can occur or alternatively, the volume of the
material has changed, in this case it has reduced in size.

[0066]In one embodiment, the compliance indicator 200 has a clear,
tooth-colored, or esthetically pleasing polymer reservoir well, chamber
or housing 201. A transparent or translucent semi-permeable membrane 202
separates the content within the reservoir chamber 201 from the external
oral environment. The content(s) within the reservoir chamber 201 depends
on the overall strategy to monitor compliance. In one implementation,
contents diffuse out from the reservoir chamber 201, through the membrane
202, into the external environment. For example: the content can be an
FDA approved visible dye which diffuses from the chamber 201, through the
membrane 202, and into the external oral environment. When the content is
emptied, the content color diminishes in brightness and value. Colorants
that are permitted for direct addition to human food by the US FDA
include annatto extract, beta-carotene, beet powder, canthaxanthin,
caramel color, carrot oil, cochineal extract (carmine); cottonseed flour,
fruit juice, paprika, riboflavin, saffron, turmeric, vegetable juice,
FD&C Blue No. 1 (brilliant blue) and No. 2 (indigotine), FD&C Green No. 3
(fast green FCF), FD&C Red No. 3 (erythrosine) and No. 40 (allura red),
FD&C Yellow No. 5 (tartrazine) and No. 6 (sunset yellow). Other food
colorants such as those found at FDA's Center for Food Safety and Applied
Nutrition website: http://www.cfsan.fda.gov/-dms/col-toc.html can be used
as well.

[0067]In another implementation, matter from the external environment
diffuse in, and reacts with the contents 204 within the reservoir chamber
201. For example, glucose molecules from the external environment diffuse
through the membrane 202, and reacts with enzymes inside the content and
the resultant enzymatic products interact with other reactants inside the
content to cause color change. As more glucose molecules diffuse in,
content color increases in brightness and value. A convenient enzyme
system is glucose oxidase and horseradish peroxidase. The first enzyme,
glucose oxidase, catalyzes the oxidation of glucose to form gluconic acid
and hydrogen peroxide. Hydrogen peroxide then reacts with
3-3,5,5'-tetramethylbenzidine (TMB) under catalytic action of horseradish
peroxidase to convert yellow TMB to green. Other colorants, such as
potassium iodide (green to brown) may also be used. These enzymes can be
immobilized within the chamber. The rate of reaction, and hence color
change, can be controlled by selecting the permeability of the membrane
202, the concentration of reactants inside the chamber 201, and the
method of delivery. The rate of reaction or concentration of the glucose
molecules can also be detected through spectroscopy or other analytical
testing. Test results will correlate with compliance to treatment.

[0068]Referring now to FIGS. 3A and 3B, another embodiment of an
indication attachment device is shown. In the embodiment of FIG. 3A, a
porous polymer material is provided on a sheet 300. The polymer material
is disposed on the sheet 300 as one or more containers 304. The container
304 may be a well as disclosed above in the discussion of FIGS. 2A-2C.
After a predetermined period of usage, the polymer material changes
appearance, for instance, changes either to the color or the size as
shown in FIGS. 2B-2C. Other implementations can include colored polymers
(both thermoplastic and thermoset materials) and composites utilizing the
same compliance mechanism as the porous polymer material.

[0069]The compliance indicator of FIGS. 3A-3B thus can be a dye
encapsulated in a polymer which is released in the presence of oral
fluids. The dye can be colorants that react with the oral fluids and that
are released from the polymer. The polymer can be porous polymer such as
monolithic porous polymer (currently used in chromatography), PVS, a high
internal phase emulsion (HIPE polymer currently used in drug release) or
any macroporous polymer. The dyed polymer will be constructed into a
small button that can be bonded to the exterior of the aligner. The
amount of dye loss will correspond with the amount of time the aligner
was in use. The pore size of the polymer and the particle size of the dye
will affect the rate of diffusion of dye from the button to the oral
fluids environment and depending on compliance needs, these factors can
be controlled.

[0070]Porous polymers are prepared by adding "porogens" during the
polymerization process of resins. Porogens are soluble in the monomer but
insoluble in formed polymers. As polymerization occurs, pores are formed
in the spaces where porogens are found. The newest type of porous
polymers is known as "high internal phase emulsions" ("HIPE"). HIPE
structures have pore diameters much larger than previous porous materials
which had only pore diameters in the angstroms.

[0071]Another porous polymer is the monolithic porous polymer currently
being used in chromatography. The polymerization of this rigid
macroporous polymer takes the shape of the mold, usually a column, into
which the monomers and porogens are poured into. Generally, the pore
volume is nearly equal to the amount of porogens added into the
monoliths.

[0072]Referring now to FIGS. 4A and 4B, a button embodiment of an
indication attachment device 400 is shown. In this embodiment, a
biodegradable polymer material is attached to either a tooth or a dental
appliance. After a certain period of use, the polymer material either
changes shape or size or color, and as shown in FIG. 4B, the volume of
the biodegradable polymer material is subsequently reduced. In one
embodiment, the button is a biodegradable polymer button. The button can
be molded from a biodegradable polymer and bonded to the exterior of the
aligner. The button will have a predetermined degradation period such as
a two week degradation period in the constant presence of oral fluids.
Potentially the polymer can be colored for a more visible indication of
the degradation of the button. The size and material will determine the
degradation period of the button. However, other factors such as brushing
of the aligner and rinsing will have to be taken into consideration when
determining the optimal degradation time of the button.

[0073]The degradation products often define the biocompatibility of a
polymer. Synthetic biodegradable polymers are favored over natural ones
because of reliability of raw materials. The following is a list of
common biodegradable polymers: polyglycolide (PGA), polylactide (PLA),
1-lactide (LPLA), poly(dl-lactide) (DLPLA), poly(E-caprolactone) (PCL),
polydioxanone (PDO), poly(glycolide-co-trimethylene carbonate) (PGA-TMC),
and polyorthoesters.

[0074]FIG. 5 shows yet another embodiment of an indication attachment
device. In this embodiment, an appliance 416 receives an adhesive dye
matrix 412. The matrix 412 is sealed either at one end or both ends using
a backing film 410. The material in the matrix 412 can be released on the
sides between the appliance 416 and the film 410 or between the two
backing films. An opening 418 may be provided in the appliance 416 and
one side of the backing film to facilitate dye release. In one
implementation, a transdermal patch may be applied in a manner similar to
drug releasing transdermal patches. Instead of embedding and releasing
drug in the adhesive matrix, a dye is released and the mechanism for dye
loss is moisture (oral fluids). In one implementation, appliance wear
compliance is indicated by the color of the adhesive layer: the more dye
lost, the longer the wear time.

[0075]FIG. 6 shows yet another embodiment where the wear indication is
achieved through a water dissolvable film. In this embodiment, an opaque
water soluble film 420 is positioned to cover one or more colored areas,
regions, spots, or dots 422 on an appliance or on a tooth. The dots 422
can be a series of colored dots with varying thicknesses of film 420 and
each exposed color corresponds to a different amount of appliance wear
time. In the embodiment where the dots 422 are imprinted on the
appliance, the film 420 is layered onto the surface of the appliance. The
mechanism of releasing dye is moisture (oral fluids).

[0076]FIG. 7 shows another embodiment where a tooth attachment 444A is
made with a dye-releasing composite. The dye-releasing composite 444A
bonded to a tooth will be covered by an appliance 416. Over time, the
dye-releasing composite 444A has a reduced or no color loss compared to
the loss for a dye on an uncovered tooth attachment 444B. The color of
the attachment will correspond to the amount of aligner wear. The
mechanism of dye releasing is moisture (oral fluids) in this embodiment.

[0077]In yet other implementations, a diagnostic indicator can be
provided. The diagnostic indicator is similar in device construction to
the compliance indicator, and utilizes the inwards diffusion strategy,
where biochemical analytes from the external environment are allowed to
diffuse through the membrane to react with the contents within the
reservoir chamber. Thus, biomarkers from the external environment diffuse
through the membrane, and react with reagents inside the content to
directly or indirectly induce color change or chemical change that can be
quantified through human eye or laboratory testing or computerized vision
systems. As more biomarkers diffuse into the diagnostic indicator, the
content color changes, for example increases in brightness and value.
Possible biomarkers include enzymes, pH, glucose, salt, oral film,
plaque, microorganisms that may exist in the oral cavity and amount of
oral fluids.

[0078]In one embodiment shown in FIG. 8, the compliance indicator can be a
time temperature indicator 480. The indicator 480 is intra-orally placed
in the mouth (either directly on a tooth or on an appliance 470) and
provides an indication of the time the indicator has been at a
preselected intra-oral temperature environment.

[0079]In yet another embodiment shown in FIG. 9, a plurality of brushes
502 having a colored fiber 504 is positioned on the appliance 500. As the
brush 502 is gradually eroded by wearing the appliance 500, a dye or
other suitable indicia of wear in the fiber 504 is exposed for visual
detection by a human or by a machine. Alternatively, the brushes 502 can
be placed on one or more teeth instead of on the appliance 500.

[0080]In yet another embodiment, the compliance indication is human
readable by changing physical or mechanical or visual properties that are
readily observable by a human. In other embodiment, the compliance
indication is machine readable. For instance, in one embodiment that
alters the electrical characteristics of an appliance during wearing of
the appliance, an electrical measurement can be made by a computer for
detecting compliance. In another embodiment that uses biomarkers, a
computer with biomarker sensor can be used with suitable computer program
to detect compliance. In yet another embodiment, a color change can be
detected by a computer vision program to detect compliance.

[0081]Each computer program is tangibly stored in a machine-readable
storage media or device (e.g., program memory or magnetic disk) readable
by a general or special purpose programmable computer, for configuring
and controlling operation of a computer when the storage media or device
is read by the computer to perform the procedures described herein. The
inventive system may also be considered to be embodied in a
computer-readable storage medium, configured with a computer program,
where the storage medium so configured causes a computer to operate in a
specific and predefined manner to perform the functions described herein.

[0082]Dental and periodontal therapies may be simultaneously delivered by
an elastic repositioning appliance to provide uninterrupted orthodontic
treatment while treating other conditions. Such therapies include
fluoride treatment to prevent or treat tooth decay, antibiotic or drug
therapy to treat gingivitis and periodontitis, bleaching to improve the
cosmetic appearance of the teeth, and/or breath freshening to treat
halitosis. In addition, such an elastic repositioning appliance may also
comprise a material which changes a visual characteristic of the shell in
response to a change in the environment, as stated previously.

[0083]Each of the above identified therapies involves one or more
therapeutic agents which are delivered to the oral environment. The
present invention provides a tooth positioning appliance coupled to means
for releasing one or more of these agents to the oral environment. Agents
for the above identified therapies include, but are not limited to,
various forms of fluoride, such as neutral sodium fluoride and stannous
fluoride, various antibiotics, such as chlorhexidine and tetracycline,
bleaching ingredients, such as carbamide peroxide, and breath fresheners
or flavors. Means for releasing the agent may include a number of
embodiments.

[0084]In one embodiment, means for releasing the agent to the oral
environment comprises a layer including the agent formed over at least a
portion of the surfaces of the polymer shell. Such a layer may comprise
the agent 1001 itself. This is illustrated in FIG. 10, which depicts a
cross-sectional view of a polymer shell 1002 having cavities 1003, shaped
to receive and resiliently reposition teeth, and an agent 1001 attached
to its surface. It may be appreciated that the depictions of the agent is
for illustration purposes and does not necessarily reflect the actual
shape, size relationship or distribution of the agent particles. This
applies to all depictions of agents hereinafter. Such attachment or
formation of the layer may be achieved by applying the agent 1001 to the
surface of the shell 1002 by a number of methods, including spraying,
painting and/or dipping. Thus, when the oral delivery appliance 1000 is
placed over the patient's teeth, the agent may then be released to the
oral environment. When the agent 1001 is attached to the inside surface
of the appliance 1000, as shown in FIG. 10, the agent may directly
contact the teeth and/or gingiva. This may be best suited for treatments
such as fluoride or antibiotic therapy which benefit from direct contact
with the teeth and/or gingiva. However, other treatments, such as breath
freshening, may most benefit from attachment to the outer surface of the
appliance 1000. Therefore, agents 1001 may be attached to any or all
surfaces of the appliance 1000.

[0085]In another embodiment the appliance 1100 can include a layer that
comprises the agent 1001 present in a carrier or binder. A common carrier
for suspension of an agent is a semisolid material, such as a gel, jelly
or putty. As depicted in FIG. 11, such semisolid material 1104 may be
applied to the surface of the shell 1102 by spraying, painting and/or
dipping to form a coating or film. Alternatively, as depicted in FIG. 12,
the semisolid material 1204 may be deposited in the cavities 1203 of the
polymer shell 1202 which are shaped to receive the teeth. The cavities
1203 may be filled to any desired level such that when the appliance 1200
is positioned over the teeth, the teeth will directly contact the
material 1204 and displace any extra material 1204. Delivery of an agent
1201 by the use of such a material 1204 is most common in bleaching and
fluoride treatments, however any type of agent 1201 may be used.

[0086]Another type of layer is a controlled-release material impregnated
with the agent, wherein the rate controlling material controls the rate
at which the agent is released from the layer. Controlled-release or
rate-controlled materials deliver an agent at a predetermined rate. As
previously described, such delivery may be achieved by a number of
methods. First, the agent may be released by diffusion through the
controlled-release material. In this case, the agent is typically present
as finely dispersed particles in a polymer matrix membrane. This is often
termed a monolithic dispersed type system, monolithic device, or matrix
diffusion system. As the concentration of agent is reduced in the matrix
due to diffusion delivery to the oral environment, the slope of the drug
diffusion curve is also reduced. The agent delivery rate decreases over
time as the material is depleted. Hence, the characteristic release
profile of a monolithic system follows an asymptotic curve; after an
initial burst of rapid release, the elution approaches a constant rate.
Second, the agent may be released by degradation of the
controlled-release material. Degradation may be achieved by a number of
mechanisms, including enzymatic degradation by enzymes in the saliva. The
agent may be encapsulated or contained in a biodegradable material, such
as a polymer matrix. Any number of degradation rates may be achieved by
manipulating the molar ratio of the monomers in the matrix. Further, the
agent may be released by a combination of diffusion and degradation of
the releasing layer. Alternatively or in addition, the agent may be
released by elution from pores within the releasing layer. Depending on
the structure of the layer, elution from the pores may be achieved by a
number of methods. If the agent is contained in a controlled-release
material which fills the pores, the agent may be released from the
controlled-release material by diffusion and/or degradation and then
elution from the pores themselves.

[0087]One attribute of controlled-release materials is that they may be
provided in a solid form, such as a thin film or sheet, which may be
attached to the polymeric shell of an elastic repositioning appliance.
Referring to FIG. 13, a controlled-release material 1305 containing the
agent 1301 may be provided as a sheet 1306 and used in the formation of
an appliance of the present invention. Here, the sheet 1306 may be
layered with an elastomeric polymer sheet 1307 over a mold 1308 of the
patient's dentition. Together the sheets 1306, 1307 may be vacuum formed
over the mold 1308 to form the repositioning appliance. By placing the
controlled-release material sheet 1306 between the mold 1308 and the
polymer sheet 1307, as shown, the controlled-release material 1305 will
cover the inside surfaces of the appliance and will be positioned against
the patient's teeth and/or gums when the appliance is in place. This may
be most beneficial for elution of agents 1301 such as fluoride,
antibiotics or bleaching materials.

[0088]Alternatively, the controlled-release material 1405 may be attached
to the polymeric shell 1402 of the oral delivery appliance 1400 after
forming the appliance. As shown in FIG. 14, the controlled-release
material 1405 containing the agent 1401 may be laminated, bonded or
otherwise attached to a surface of the polymer shell 1402 in a desired
area. Such attachment may be removable, so that the material 1405 may be
removed when the agent 1401 has substantially eluted or the therapy is to
be discontinued, or it may be non-removable, so that the material 1405 is
present throughout the life of the appliance. Also shown in FIG. 14 is
the use of a controlled-release tablet 1409 which may be inserted into a
pocket 1410 or portion of the polymeric shell 1402 of the appliance 1400.
Portions of the pocket may be perforated or meshed to facilitate delivery
of the agent. The agent may then elute from the tablet 1409 into the oral
environment over time. This design may be most applicable to elution by
degradation of the tablet 1409, wherein the tablet 1409 may be replaced
periodically for renewed delivery.

[0089]In a further embodiment, the releasing means comprises a reservoir
formed in the polymer shell in addition to the cavity which receives the
teeth. Reservoir devices or membrane diffusion systems can supply an
agent or substance at a constant rate under sink conditions. These
systems consist of three elements: a reservoir containing the agent, a
low concentration sink, such as the oral environment, and a
rate-controlling membrane separating the reservoir from the sink. The
system obeys Fick's Law of Diffusion for the mass flux across the
membrane. Thus, the system is held at a constant delivery rate based on
the diffusion coefficient through the membrane.

[0090]Referring to FIG. 15, the releasing means is shown to comprise a
reservoir 1511 formed in the polymer shell 1502, in addition to the
cavity 1503 which receives the teeth. The reservoir holds the agent 1501
and is covered by a rate controlling membrane 1512 which controls the
rate at which the agent 1501 is released from the reservoir 1511. The
reservoirs 1511 are depicted as being located substantially within the
wall of the polymer shell 1502 for elution to the cavity 1503. However,
it may be appreciated that reservoirs 1511 may be located anywhere in the
shell 1502, may be external to the wall of the shell 1502 and may elute
in any direction. The reservoirs 1511 may be pre-filled with the agent
1501 to be released. That is, the appliance 1500 is provided with the
reservoirs 1511 filled with the agent 1501. In this case, the reservoirs
1511 may be sealed by the membrane 1512 as depicted in FIG. 15. However,
the appliance 1600 can include a reservoir 1611 formed in the polymer
shell 1602, in addition to the cavity 1603 which receives the teeth. The
reservoirs 1611 may also be accessible to the user so that the reservoir
may be replenished with agent 1601 as desired. In this case, the
reservoir 1611 may be not be sealed by the membrane 1612 as depicted in
FIG. 16.

[0091]In another embodiment, the agent 1701 is supported by a carrier. As
depicted in FIG. 17, the carrier comprises a binding material 1713 which
releasably binds the agent 1701 to a surface of the polymeric shell 1702
of the appliance 1700. The binding material 1713 may release the agent
1701 by a number of mechanisms, including dissolution of the binding
material 1713, activation or deactivation of the binding material 1713 or
any other release mechanism.

[0092]In a further embodiment, as depicted in FIG. 18, the polymeric shell
1802 of the oral delivery appliance 1800 is comprised of a
controlled-release material 1805 containing an agent 1801. In this case,
the controlled-release material 1805 itself is formed to function as a
repositioning appliance. This may be achieved by vacuum forming a sheet
of controlled-release material over a mold of the patient's teeth. The
agent 1801 may then elute from the appliance 1800 by means of diffusion
or other release mechanisms.

[0093]Means for releasing the agent to the oral environment have been
described in a number of embodiments, above, in regards to the agent
itself. However, in each embodiment, the agent may first be encapsulated
or microencapsulated in a material, typically a polymer. Such
encapsulation may be desired or necessary to protect the agent from the
effects of processing. For example, some agents may be hydrolyzed or
denatured by processes such as extrusion or thermoforming which may be
involved in the production of the appliance. Encapsulation may also
protect the agent from environmental factors throughout the shelf-life of
the appliance. Therefore, in the above descriptions and throughout,
"agent" may identify the agent itself or an encapsulated agent.

[0094]Agents may be encapsulated or entrapped by a number of materials.
Such materials may include polylactic acids, polycapric lactones,
polyvinyl alcohols, polyacrylic acids, polyethylene oxides, polylactide
glycolic biodegradable polymer capsules and side-chain crystallizable
polymers, to name a few. Encapsulation may be achieved by a variety of
processes. Particularly, the agent may be encapsulated by spray-drying.
For example, the agent may be mixed or combined with a solvent, such as
polyvinyl alcohol, and then combined with a polymer resin. After the
solvent evaporates, polymer microcapsules, each containing the agent
dispersed throughout its matrix, are retained.

[0095]The encapsulating or entrapping material may or may not provide
controlled-release of the agent from the microsphere. If the
encapsulating material does provide controlled-release capabilities, such
a layer would be in addition to any controlled-release means for
releasing the agent previously described. For example, the encapsulated
agent may be dispersed throughout a sheet of controlled-release material
which is later attached to the polymeric shell of an elastic
repositioning appliance. When the appliance is positioned in the
patient's mouth, the agent may elute at a controlled rate based on the
release of the agent from the encapsulating material and from the sheet
of controlled-release material.

[0096]Similarly, the encapsulating material may be an ion exchange resin.
Such resins have a very high surface area and are able to absorb a large
quantity of an agent for controlled-delivery. An exemplary resin is sold
under the trademark MICROSPONGE (Advanced Polymer Systems), and
described, for example, in U.S. Pat. No. 5,145,675, the full disclosure
of which is incorporated herein by reference. In addition to serving as
an encapsulating material, ion exchange resins may be used for as a
controlled-delivery material in any of the above described embodiments.

[0097]In some instances it may be desirable to change a visual
characteristic of the polymeric shell of an oral appliance. Such
appliances comprise a polymeric shell 1902 having a cavity 1903 shaped to
be removably placeable over the teeth and a material on or within the
shell that changes a visual characteristic of the shell. Such a change is
typically in response to a change in the environment. For example, the
material may be a dye which changes color when the appliance is removed
from the patient's mouth and changes temperature due to the change in
environment. This gradual color change is illustrated in FIG. 19. For
example, as shown, a transparent oral delivery appliance 1920 will remain
transparent when it is in the mouth and maintained at body temperature.
Upon removal from the mouth, the appliance will cool to room temperature.
As the appliance begins to cool, the colorant will gradually become
visible, as illustrated in the tinted oral delivery appliance 1930. As
the appliance equilibrates to room temperature, the colorant will become
more visible, as illustrated in the colored oral delivery appliance 1940.

[0098]The color may be dispersed throughout the appliance, as in FIG. 19,
or the color may be localized in a specific area within or on a surface
of the appliance. As shown in FIG. 20, the appliance 2000 may contain,
for example, a stripe 2014 of color or dye in a specific location. Such a
stripe 2014 may be visible at all times or it may only appear when
removed from the oral environment. In either case, the stripe 2014 may be
positioned so that it is hidden from view, i.e. along the lingual
surfaces or along the molars, or it may be placed anywhere along the
appliance. 2000. Likewise, a portion of material 2015 which changes a
visual characteristic may be attached, bonded or laminated to a surface
of the polymer shell 2002, either removably or permanently.

[0099]Portions of the system and corresponding detailed description are
presented in terms of software, or algorithms and symbolic
representations of operations on data bits within a computer memory.
These descriptions and representations are the ones by which those of
ordinary skill in the art effectively convey the substance of their work
to others of ordinary skill in the art. An algorithm, as the term is used
here, and as it is used generally, is conceived to be a self-consistent
sequence of steps leading to a desired result. The steps are those
requiring physical manipulations of physical quantities. Usually, though
not necessarily, these quantities take the form of optical, electrical,
or magnetic signals capable of being stored, transferred, combined,
compared, and otherwise manipulated. It has proven convenient at times,
principally for reasons of common usage, to refer to these signals as
bits, values, elements, symbols, characters, terms, numbers, or the like.

[0100]It should be borne in mind, however, that all of these and similar
terms are to be associated with the appropriate physical quantities and
are merely convenient labels applied to these quantities. Unless
specifically stated otherwise, or as is apparent from the discussion,
terms such as "processing" or "computing" or "calculating" or
"determining" or "displaying" or the like, refer to the action and
processes of a computer system, or similar electronic computing device,
that manipulates and transforms data represented as physical, electronic
quantities within the computer system's registers and memories into other
data similarly represented as physical quantities within the computer
system memories or registers or other such information storage,
transmission or display devices.

[0101]The terms and expressions which have been employed in the foregoing
specification are used therein as terms of description and not of
limitation, and there is no intention, in the use of such terms and
expressions, of excluding equivalents of the features shown and described
or portions thereof, it being recognized that the scope of the invention
is defined and limited only by the claims which follow. For example,
although films or appliances have been disclosed as mechanisms for
compliance measurement, droplets can be used to deliver the compliance
indicating substances to the patient as well. Other embodiments for
compliance indication can be used as well. Whereas particular embodiments
of the present invention have been described herein for purposes of
illustration, it will be evident to those skilled in the art that
numerous variations of the details may be made without departing from the
invention as defined in the appended claims.